Process for removing the halphen test response from cottonseed oil



United States Patent 3,135,775 PROCESS FOR REMOVING THE HALPHEN TEST RESPONSE FROM COTTONSEED OIL Eric T. Rayner, 2682 Clover St., New Oleans 22, La.; Dorothy C. Heinzelman, 718 Jefierson Ave., New Orleans 15, La.; and Harold P. Dupuy, 17 Warbler St., New Orleans 24, La. N0 Drawing. Filed May 10, 1963, Ser. No. 279,643 5 Claims. (Cl. 260-424) (Granted under Title 35, US. Code (1952), see. 266) A non-exclusive, irrevocable, royalty-free license in the invention herein described through the world for all purposes of the United States Government, with the power' to grant sublicenses for such purposes, is hereby granted to the Government of the United States of America.

This invention relates to a process for removing the Halphen test response from cottonseed oil and has as its object the production of cottonseed oils that react negatively to the Halphen test.

Cottonseed oil, in addition to the major fatty acid constituents, is reported to contain some one to two percent of malvalic acid. Malvalic acid reacts positively to the so-called Halphen test. Cottonseed oil also reacts positively to the Halphen test as do the seed oils of many malvaceous plants.

It is known that acids containing the cyclopropene ring (i.e., malvalic annd sterculic acids), when included in the rations of laying hens, are capable of producing certain abnormalities such as pink egg whites, salmon colored, enlarged, and fluid yolks. In addition, it has been reported that a correlation exists between the intensity of the Halphen test as applied to the residual oil in the cottonseed meal component of a poultry ration and the occurrence of abnormalities in stored intact eggs.

Prolonged heating of cottonseed oil has been reported to eliminate the Halphen test response but this is not practical for cottonseed oil, the intended end use for which is an edible use, since prolonged heating of vegetable oils in the presence of air is known to produce toxic polymers.

Certain mineral acids are also reported to effect a reduction of or the destruction of Halphen test response. but the addition of an extraneous substance to edible oil without provision for the complete removal thereof, subsequently, is most undesirable. Moreover, our own experiments show that some acids generally are ineffective of themselves and require, in combination, extensive heating of the oil which heating, as we note above, is undesirable. In general, the process of our invention which we use to eliminate the Halphen test response from cottonseed oil consists of treating the oil with a reagent containing a plurality of either carboxyl groups, potential carboxyl groups, or acid groups and employing therewith a temperature of up to 225 C. for intervals of time sufiicient to completely eliminate the Halphen test response. The heating of the oil is carried out in an inert atmosphere.

We have discovered that among other things, small quantities of selected polycarboxylic compounds or polybasic acids are capable, possibly by reason of their inherent propitious solubility characteristics with respect to the oil, of eliminating With dispatch the Halphen test response in cottonseed oil. Since the presence of any extraneous substance, and this applies with no less force to the selected reagents of our process, is per se undesirable in an oil intended for edible purposes, We have designed our process so that besides eliminating the Haiphen test response, complete removal is provided for the particular reagent We employ. Thus, a crude cottonseed oil can be treateed according to the process of our invention annd a subsequent step, which step consists of passing the oil in a suitable solvent through a column of conventionally used chromatographic alumina, will produce, after application of established methods of solvent removal, a finished cottonseed oil of acceptable appearance which is completely free of Halphen test response and devoid of any extraneous reagent employed in the elimination of this test response. Furthermore, the specific method which we employ is equally applicable and eflective when applied either to refined cottonseed oil or to the unrefined, crude oil. As will be appreciated by those versed in the art of vegetable oil refining, the heating of crude oil at even the relatively low temperatures required by our process tends to fix the naturally occurring color bodies and make diificult the production of a finished oil with acceptable color characteristics. The two step method which characterizes this invention circumvents entirely such color problems which may be associated with the application of our process to crude cottonseed oils.

It is our opinion that the polyfunctional reagent we employ reacts with the material responsible for Halphen test response and subsequently, the combined reaction product (reagent plus the material responsible for the test response) is removed entirely from the oil by the treatment with alumina. Although we are by no means certain that this is the mechanism of our process, inability to explain the reaction in no way detracts from the efficacy of the process. We are able to demonstrate by chemical test the complete elimination of Halphen test response in cottonseed oils treated by our process. We are able to demmonstrate by means of appropriate phosphorous or ultraviolet analysis, and this is of paramount importance in a process of this type, the complete absence of residual reagent in the finished oil.

Two chemical test methods were used for measuring Halphen test response in our examples which follow; namely, the A.O.C.S. Halphen Test, Ofiicial Method Cb 125 and the spectrophotometric method of Deutschman and Klaus as published in Anal. Chem. 32, 1809 (1960). Reduction in Halphen test response was calculated from the ratio of the absorbance per unit weight of treated and refined oils as obtained in the recommended procedure.

The ultraviolet data listed in our examples reflect the absorbances of the various oil when measured at 315.5 mu. It was found that a solution of trimellitic acid anhydride in a non-cyclopropenoid oil, namely corn oil, had a maximum absorption band at this Wavelength. It was similarly found that the trimellitic acid anhydride-cyclopropenoid reaction product as present in the treated cotonseed oils also had a maximum absorption band at 315.5 mu. Consequently this Wavelength was used to establish the presence or absence of the aromatic polybasic acid or anhydride reagents used in this process.

The phosphorous analyses listed in our examples which were employed to establish the presence or absence of phosphoric acid reagent or phosphorous containing reaction products were obtained by the A.O.C.S. Oificial Method Ca 12-55.

EXAMPLES Portions of cottonseed oil were heated under nitrogen at various temperatures and for varying intervals of time with difierent proportions of several appropriate polycarboxylic acids or ortho-phosphoric acid and the resulting oils tested for the Halphen response after treatment. Some selected data from the manifold experiments which we performed for the purpose of establishing optimum operating limitations for our method are shown in tabular form in Table I.

TABLE I The Treatment of Cottonseed Oll Wlth Acza's or Aczd Anhydrldes to Accelerate the Reduction of the Cyclopropenozd Content and t FtIClllltIle the Elzmmatlon 0f the Cyclopropenozds From the 011 Acid or Acid Anhydride Heat Nature of Product 7 Treatment e Cottonseed oil Type Concentration Type 0.) (hrs.) Halphen Absorp- Phosphortest b tivity, 0115, Percent (M) 315.5 m percent Crude Oil. 0. 05970 Do 0. 10200 Do Do Do a Alkali refined DO- do 225 o 225 l Trimellitic acid anhydride.-- 2 0. 092 225 1 0 2 0.092 225 1 Pyromellitic dianhydride. 1 0. 04 200 1 Mellitic acid l 0. 026 225 1 Ortho-phosphoric acid )4 0.026 180 1 .d0 0.026 180 1 do A 0.051 180 V2 Citric acid 1 O. 046 225 3 Maleic acid- 1 0. 076 225 l Succinic acid 1 0. 076 225 2 N one"- Trimellitic acid anhydride 1 0. 046 225 0.1 0. 08990 8 Heat treatment of the oil carried out under nitrogen.

b Halphen response measured by two procedures: (1)Modified A.0.C.S. Method Ob 1-25.

I.S.; Anal. Chem. 32, 1809 (1960).

(2) Deutschman, A. 3., Jr. Klaus,

Ultraviolet analysis was employed to ascertain the presence or absence of aromatic polybasic acid or anyhdride reagents used in the modification and subsequent removal of cyclopropenoids from treated oils.

These reagent treated oils were passed through an alumina column as described in the text.

9 Indicates presence of a peak of maximum absorption at 315.5 m

1 Phosphorous analysis determined by A.O.C.S. Official Method Ca 12-55.

- 1 Negative control.

In all of those cases where elimination of the Halphcn test response was complete, a subsequent chromatographic treatment with alumina (40 grams of oil through a 40 mm. ID. column packed with 400 grams of 200 mesh activated alumina, and eluted with volumns of petroleum ether) was carried out on the Halphen-acid free oil in order to remove all traces of thereagent used in eliminating the Halphen test response. Additional oil can be passed through the column until the absorbing power of the column has been exhausted. The successfully treated oils, following the alumina treating step and removal of solvent were subjected to (appropriate) ultraviolet (or phosphorus) analysis in order to assure that complete removal of reagent had been accomplished. The pertinent data so obtained is presented in tabular form in Table I. 7

Having thus described our invention, we claim:

1. A process for eliminating Halphen test response in cottonseed oil comprising the steps:

v (a) treating the cottonseed oil in an inert atmosphere at a temperature of about from 180 to 225 C.

about from to 2% by weight based on the weight of the oil of a reagent selected from the group consisting of mellitic acid, trimellitic acid anhydride, pyrornellitic dianhydride, and ortho-phosphoric acid,

(b) cluting the reagent treated and heated oil of step (a) in petroleum ether (boiling range 3060 C.) through a column of alumina,

(c) removing the solvent from the reagent treated and eluted oil from step (b).

2. The process of claim 1 wherein the reagent is mellitic acid.

3. The process of claim 1 mellitic acid anhydride.

4. The process of claim 1 wherein the reagent is' pyromellitic dianhydridc.

5. The process of claim 1 wherein phosphoric acid.

the reagent is ortho- No references cited.

wherein the reagent is tri- 

1. A PROCESS FOR ELIMINATING HALPHEN TEST RESPONSE IN COTTONSEED OIL COMPRISING THE STEPS: (A) TREATING THE COTTONSEED OIL IN AN INERT ATMOSPHERE AT A TEMPERATURE OF ABOUT FROM 180* TO 225*C. FOR A PERIOD OF ABOUT FROM 0.5 HOUR TO 2 HOURS, WITH ABOUT FROM 1/4% TO 2% BY WEIGHT BASED ON THE WEIGHT OF THE OIL OF A REAGENT SELECTED FROM THE GROUP CONSISTING OF MELLITIC ACID, TRIMELLITIC ACID ANHYDRIDE, PYROMELLITIC DIANHYDRIDE, AND ORTHO-PHOSPHORIC ACID, (B) ELUTING THE REAGENT TREATED AND HEATED OIL OF STEP (A) IN PETROLEUM ETHER (BOILING RANGE 30-60*C.) THROUGH A COLUMN OF ALUMINA, (C) REMOVING THE SOLVENT FROM THE REAGENT TREATED AND ELUTED OIL FROM STEP (B). 